Oz Blog News Commentary

Latest on coronavirus transmission

June 28, 2020 - 18:34 -- Admin

Renyi Zhang, from
Texas A&M University, and colleagues have published a paper (June 11) in
the Proceedings of the National Academy of Sciences of the USA in which they determine
the dominant method of transmission of Covid-19. They analysed trends and
mitigation measures from January 23 to May 9 in three epicentres (Wuhan, Italy
and New York City). Covid-19 broke out in Wuhan in December 2019. The numbers of
confirmed infections and fatalities in China dominated the global trend during
January and February 2020, but in China these have declined sharply since
February. The epicentre shifted from Wuhan to Italy in early March and to New York City (NYC)
in early April. By April 30, the numbers of confirmed Covid-19 cases and deaths, respectively, reached
over 200,000 and 27,000 in Italy and over 1,000,000 and 52,000 in the United
States, compared to about 84,000 and 4,600 in China. The cases and fatality curves in Italy have slowed since mid-April, while the numbers in
the world and the United States continue to increase. At the time of writing of
this article (June 28), China was still getting about 20 new cases per day (total
cases 84,726; deaths, 4,641); Italy about 175 new cases per day (total cases 240,136;
deaths 34,716); and the USA about 40,000 new cases a day (total cases
2,590,282; deaths 128,108). Globally, the number of cases has now passed 10
million, with a daily increase of nearly 200,000, while the number of deaths
has now passed 500,000, and is increasing at over 4,000 per day2,3.

Zhang and colleagues analysed the trend and
mitigation measures in the three epicentres. Their results showed that the
airborne transmission route is highly virulent and is the dominant mode of
spread for Covid-19. They were able to discern the most effective mitigation
measures from the trends of the pandemic in the various epicentres. Their
analysis has shown that the use of a face mask is the dominant factor in shaping
the trends of the pandemic. It is the single protective measure that has most significantly
reduced the number of infections. Other mitigation measures, such as social
distancing, implemented in the United States and in many other places,
including Australia, were insufficient by themselves in protecting the public. Their
work has also demonstrated that sound science is essential in decision-making
for the current and future public health pandemics1. It is also
important that we learn from what worked this time around, ready for the next
one, which will come. Taiwan learned this in 2003.

Taiwan suffered 346 cases and 73 deaths
from the SARS virus in 2003 which, being of the coronavirus family and closely
related to the virus that causes Covid-19, is transmitted much the same way; by
airborne droplets from coughing, sneezing or talking. As a consequence, when
Covid-19 raised its ugly head, Taiwan struck hard and struck early, and started
shutting down travel in December 2019, before it had its first confirmed case. Australia
didn’t start doing that sort of thing until much later4. In addition,
Taiwan’s relatively low COVID-19 transmission rate is attributed to the fact
that a majority of people in the country wore face masks in public5.
In Australia only a very small minority of people have worn face masks in
public. Wearing a face mask may not necessarily prevent you from contracting
the virus (although it is 70% effective), but it is even more likely stop you
from transmitting it5. One factor which also had an impact in
Australia, as in the USA, was the cultural aversion to wearing face masks. As a consequence, Taiwan, in which wearing
masks is not uncommon in ‘normal’ times, and which has a similar population to
Australia, had only had 447 cases and 7 deaths from Covid-19, while Australia
has had 7,641 cases and 104 deaths2. The ‘she’ll be right’ or ‘I’m
alright, jack’ attitude may be our enemy. We should learn from other countries’
successes and not have to learn from our own mistakes again and again. People’s
lives depend on it.